Question 1

What is ICD-10 code N10?

Accepted Answer

N10 is the ICD-10-CM diagnosis code for acute pyelonephritis. A sudden kidney and upper urinary tract infection, typically caused by bacteria, presenting with fever, flank pain, and urinary symptoms. N10 sits in the ICD-10-CM chapter for diseases of the genitourinary system (n00-n99), within the section covering renal tubulo-interstitial diseases (n10-n16).

N10 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Document the causative organism when identified through culture or urinalysis.

Question 2

Is N10 an HCC code?

Accepted Answer

No. N10 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is N10 billable?

Accepted Answer

Yes. N10 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. N10 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Question 4

What is the V28 vs V24 difference for N10?

Accepted Answer

N10 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards N10 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

Question 5

What should coders know when reporting N10?

Accepted Answer

Document the causative organism when identified through culture or urinalysis Distinguish from chronic pyelonephritis (N11 codes) by confirming acute onset and duration

N10

Is N10 an HCC code?

What This Code Means

Coding Tips

Use Additional Code

Code Hierarchy

Open N10 in the Interactive Encoder